Is it possible that you have a sugar issue? I keep glucose tablets in my jersey pocket if I'm going to be out longer than 15-20 miles. Even eating right and staying hydrated sometimes isn't enough, sometimes I'm fine and sometimes my sugar is just off. Orange juice helps to if you can't talk the chalky tablets. I check ebay or the LBS occasionally for sales on shorts, I've found last years shorts or one's with a slight defect for way less. In the beginning I thought spending $80-100 on shorts was insane and got some really nice one's on ebay, the tie was cut in one and there was a mark on the other pair but they still work great. Congrats on your 30 mile milestone, I was really proud when I hit that to.